1. Field of the Invention
The present invention relates to an electronic file browsing system in which an electronic file is browsed with a mobile terminal.
2. Description of the Related Art
There is known a browsing system in which company information such as e-mails and schedules stored in a server of a company is converted to data for mobile terminals, like mobile phones, and delivered thereto so that such company information is browsed with the mobile phones outside of the company. Such browsing system is desired to enable browsing of electronic files attached to e-mails or stored in the server. However, the electronic files (hereinafter, referred to as document files) created by word-processing software, spreadsheet software, presentation software, and the like for personal computer terminals cannot be browsed with the mobile phones if the document files are delivered to the mobile phones without any conversion, because the corresponding software is not installed on the mobile phones in many cases.
In Japanese Patent Laid-Open Publication No. 2007-199983, when document files such as described above are requested to deliver, the document files are converted to image data and delivered. Owing to this, there is no need to prepare software corresponding to the document files, and contents of the document files can be browsed with mobile phones by just providing an image data viewer.
Types of image data (format such as JPEG and bitmap, resolution, image size, and the like) which can be displayed with mobile phones differ according to the model. Therefore, when document files are delivered after being converted to image data, the document files should be converted to the format corresponding to the model of the mobile phone.
Since new models of mobile phones are released one after another, the conversion function for converting document file to image data, if it is provided in the company server like the JP-A 2007-199983, needs maintenance such as registry of data for new model every time a new model is released, which takes time.
As a solution for this problem, it may be possible to make Application Service Provider (ASP) do the image conversion processing. For example, when a user requests delivery of document file, the document file is once transferred to the ASP and converted to image data by the ASP. Then, the user accesses the ASP to browse the image data of the document file with a mobile phone. This way, the maintenance of the conversion function is delegated to the ASP, so that the maintenance of the company server becomes unnecessary.
However, when the image data is browsed by the user according to the process described above, there is a possibility that unauthorized users access the ASP, which may cause information leakage. To prevent this, it is possible to perform user authentication when accessing the ASP as well. According to this method, however, the user needs to input ID or password in both time when accessing the server in the company and the server in the ASP, which makes operation troublesome.